A development blog of what Con Kolivas is doing with code at the moment with the emphasis on linux kernel, MuQSS, BFS and -ck.

Tuesday, 11 November 2014

BFS 457, linux-3.17-ck1

Finally announcing a resync and minor update of BFS for the linux-3.17(.x) kernel releases.

Only minor updates have gone into this release apart from including one of the rework patches by Alfred Chen (thanks!) and the removal of the old KVM workaround that was no longer required with the bugfixes last release courtesy of Graysky (thanks!).

I'm recompiling the kernel now with the new CK patch and the new UKSM beta patch which was coincidentally released about the same time. Thank you very much for working on this project. It helps breathe new life into old hardware.

I have an Intel desktop CPU with four cores. When I check out the idle C-states the CPU is in using the tool "i7z", I noticed only two of the cores are dropping into the C6 state when idle, while the other two cores mostly stay in C1 and only very rarely drop to C6 (basically never). This only happens when using BFS, not when using 3.17 and CFS.

This was different until the 3.16 kernel. If I for example compare 3.16.7-ck with 3.17.0-ck, .1-ck and .2-ck, on 3.16 all four cores are typically 99% in the C6 state when nothing is going on.

Is this only happening on my machine? Is this just some configuration mistake on my end?

You're welcome. Wish I knew how to display with a proportional font. Never cared for the blogspot interface... any chance of you opening up a github account for ck1? It has a very nice bug tracking system within the interface (called issues), it uses git which is a standard and will encourage others to contribute to your code, they can send you very convenient pull requests, and it's free :)